In the art of hydrocarbon recovery from subterranean formations, it is common to pump fluids through a wellbore in order to place materials in, adjacent to or extending from the wellbore. Thus, gravel is commonly placed in a near-wellbore zone in a so-called gravel pack in order to form a porous matrix through which formation fluids may be produced but which will act as a filter medium for the separation of fine formation solid materials from the fluid stream. It is also common to hydraulically fracture the rock formation adjacent the wellbore to cause radially-oriented cracks to be developed. Such fracturing operations are commonly carried out using a viscosified fluid in which solid particulate proppant materials such as sand, sintered bauxite, walnut shells, and the like, are suspended which will remain in the created fracture once fracturing pressure has been released, thereby forming a high permeability channel through which formation fluids may easily pass into the wellbore for recovery.
U.S. Pat. No. 5,330,005, describes an improved process whereby fibers are incorporated into a gravel packing or fracturing fluid so that the fibers will be intimately mixed with and deposited with the gravel or proppant materials to stabilize the gravel or proppant pack against flowback into the well due to fluid flow velocity action during fluid production from the well. The fibers used in these processes may comprise virtually any fibrous material such as glass, carbon, synthetic or metallic fibers or mixtures thereof. With glass, metal and some synthetic fibers, mixing the fibers into a viscosified carrier fluid presents little difficulty since such materials typically have a bulk density much greater than water, are generally supplied in small bundles or packets called "tows" containing several fibers which are easily wet by water and which are easily dispersed in an aqueous fluid.
Glass fibers have found use in many gravel packing and fracturing applications and are usually preferred due to their relatively low cost, their availability in relatively easily transportable bulk form and their ready availability. However, because of chemical or combined chemical and temperature interaction with certain formation and well treatment fluids such as strong acids or strongly basic fluids, a more durable, more chemically resistant fiber such as a synthetic organic or a carbon fiber must be used. With some carbon and some synthetic fibers, however, their low bulk density and low water wettability do not allow them to be easily dispersed into an aqueous treatment fluid so that they can be placed with a gravel pack or fracture proppant pack. The low bulk density also makes dry mixing the carbon fibers with proppant or gravel packing materials having much higher densities subject to segregation during transport. This density segregation is further aggravated in dry transfer operations. Furthermore, the problem of wetting and dispersion of the fibers in the fluid prior to pumping remains.